JANUARY 12, 1928
THE NEW DORNIER "SUPER-WAL
Four Gnome-Rhone "Jupiter" Geared Engines
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SEVERAL weeks ago we recorded in FLIGHT the completion
at Friedrichshafen of a new Dornier " Super-Wai " intended
for passenger-carrying. The machine has now passed its
preliminary flight tests, and although maintaining a seemly
reticence concerning weights and performance, the Dornier
Metallbauten Gesellschaft of Friedrichshafen have sent us
two photographs of this machine, and a certain amount of
information. The new " Super-Wai " is claimed to have
attained a top speed of 220 km/hr. (136-5 m.p.h.), while
the photograph of the machine on the water is stated
to represent the " Super-Wai " taking off with a total
loaded weight of 15 tons (metric, presumably). It is
not clear whether the top speed claimed was attained
with the full total loaded weight of 15 tons (33,000 lbs.)
or at some lower total weight, but assuming the former
to be the case, the Everling " High-speed Figure " is 14-2,
Constructionally the new " Super-Wai " is of normal
Dornier type, with a boat hull of Duralumin and a monoplane
wing with steel spars and Duralumin ribs and covering.
Lateral stability on the water is obtained as in previous
Dornier boats by wing stumps growing out of the hull.
The boat hull is divided into a series of compartments, in
the following order, starting from the bows : space for navi-
gating gear ; cabin for 12 passengers ; pilots' cockpit on the
port side (dual controls), wireless compartment on starboard
side ; fuel and luggage space ; and finally aft cabin with room
for 8 passengers.
The fuel compartment contains 8 petrol tanks, 4 of S00 litres
(66 gallons) each, and 4 of 600 litres (132 gallons) each,
giving a total petrol capacity of 3,600 litres (792 gallons).
With the petrol in the hull and the engines on top of the wing,
pressure feed must necessarily be employed, a system not
A MERE BAGATELLE: Two views of the new Dornier " Super- Wai" flying-boat, which is fitted with four"Jupiter" engines, It has a wing span of 93 ft. 10 in., and a wing area of 1,539 sq. ft. Note the tandem
arrangement of the wings.
which does not appear unduly high for a " Wing Power "
of 13-4 h.p/sq.m. (1-25 h.p./sq. ft.). On the other hand, if
we examine the Everling " Distance Figure " (which is, of
course, the propeller efficiency multiplied by L/D at top
speed), this is found to be 6-4, which is an unusually high
value. Thus if it is assumed that the propeller efficiency, with
the geared engines used, is 0-75, the L/D corresponding to
top speed is 8-53. It would appear somewhat doubtful
whether this is likely to be attained. Even if we increase the
propeller efficiency to 0-80. the L/D is still as high as 8. The
machine is probably very " clean " in the aerodynamic sense,
what with the small amount of wing bracing and the engines
placed in tandem, but even so, the " Distance Figure" is so
high as to make one a little suspicious. If the above value
of the " Distance Figure " is indeed correct, the " Super-
Wal " would seem to be an excellent machine for long-
distance flights, provided the structure weight is not unduly
high.
now in favour in this country, and with four engines to feed
from eight different tanks, it may be assumed that the petrol
system is far from being simple.
The photographs show quite clearly the arrangement of
the four 480 h.p. Gnome-Rhone " Jupiter " engines, which are
placed in two tandem pairs some distance out on the wing.
The engines are fitted with the Farman type of reduction gear,
so that the wooden propellers are running at one-half engine
speed. The efficiency should, therefore be good, especially
for taking off, but no data are available concerning the length
of run required.
No information is available concerning the weight empty
etc., of the " Super-Wai " but following are the main dimen-
sions :—
Length of machine overall . . 24-6 m. (80 ft. 8 in.)
Height 5-9 m. (19 ft. 4 in.).
Wing span 28-6 m. (93 ft. 9 in.).
Wing area 143 sq. m. (1,540 sq. ft.)
Mr. Bert Hinkler's Plans
THE long contemplated flight of Mr. Bert Hinkler's from
London to Australia is to commence shortly. He was forced
to postpone his plans last year owing to other demands made
upon his services which included, for instance, testing the
" Crusader " racing seaplane, etc. He will use his own Avro
" Avian," which has had the fuel capacity increased to
allow for a series of 1,000-mile stages. At this rate
of travel Mr. Hinkler should reach Australia in a fort-
night.
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